Over-expression of acetylcholinesterase stimulates the expression of agrin in NG108-15 cells.

Several lines of evidence suggest the non-cholinergic functions of acetylcholinesterase (AChE) in promoting neurite outgrowth of cultured neurons and in inducing the postsynaptic specializations of developing neuromuscular junctions. In order to support the hypothesis, a cholinergic synapse-forming cell line NG108-15 was over-expressed with chick AChE by cDNA transfection. The transfected NG108-15 cells secreted a approximately 105-kDa protein, recognized by anti-AChE antibody in Western blot analysis, corresponding to the chick AChE catalytic subunit. Over 80% of the recombinant enzyme were secreted into the conditioned medium and they were enzymatically active. In the NG108-15 cell-muscle co-cultures, the AChR-aggregating activity of NG108-15 cells was increased by the over-expression of AChE. The increase in AChR-aggregating activity of the transfected NG108-15 cells paralleled with the increase in agrin and neurofilament expression of the transfected cells as determined by their corresponding antibodies. However, the intracellular cAMP level remained unchanged in the AChE over-expressed NG108-15 cells. These results support the hypothesis that AChE could play a role in promoting neuron differentiation.